[PATCH][next] btrfs: remove shadowed declaration of variable i in for-loops

[PATCH][next] btrfs: remove shadowed declaration of variable i in for-loops

[Colin Ian King]

The variable i is declared at the start of function btrfs_qgroup_inherit
however there are two for-loops that redeclare the variable using a C99
declaration, causes name shadowing. I believe there is no need for this
local scoping of i in the loop, so replace the declaration in the loops
with assignments.

Cleans up clang scan build warnings:

fs/btrfs/qgroup.c:3194:12: warning: declaration shadows a local variable [-Wshadow]
 3194 |                 for (int i = 0; i < inherit->num_qgroups; i++) {
      |                          ^
fs/btrfs/qgroup.c:3089:6: note: previous declaration is here
 3089 |         int i;
      |             ^
fs/btrfs/qgroup.c:3321:12: warning: declaration shadows a local variable [-Wshadow]
 3321 |                 for (int i = 0; i < inherit->num_qgroups; i++)
      |                          ^
fs/btrfs/qgroup.c:3089:6: note: previous declaration is here
 3089 |         int i;
      |             ^

Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
---
 fs/btrfs/qgroup.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c
index ce446d9d7f23..b1f93dbf468c 100644
--- a/fs/btrfs/qgroup.c
+++ b/fs/btrfs/qgroup.c
@@ -3191,7 +3191,7 @@ int btrfs_qgroup_inherit(struct btrfs_trans_handle *trans, u64 srcid,
 			ret = -ENOMEM;
 			goto out;
 		}
-		for (int i = 0; i < inherit->num_qgroups; i++) {
+		for (i = 0; i < inherit->num_qgroups; i++) {
 			qlist_prealloc[i] = kzalloc(sizeof(struct btrfs_qgroup_list),
 						    GFP_NOFS);
 			if (!qlist_prealloc[i]) {
@@ -3318,7 +3318,7 @@ int btrfs_qgroup_inherit(struct btrfs_trans_handle *trans, u64 srcid,
 	if (need_rescan)
 		qgroup_mark_inconsistent(fs_info);
 	if (qlist_prealloc) {
-		for (int i = 0; i < inherit->num_qgroups; i++)
+		for (i = 0; i < inherit->num_qgroups; i++)
 			kfree(qlist_prealloc[i]);
 		kfree(qlist_prealloc);
 	}
-- 
2.39.2

Re: [PATCH][next] btrfs: remove shadowed declaration of variable i in for-loops

[David Sterba]

On Thu, Nov 30, 2023 at 03:08:11PM +0000, Colin Ian King wrote:
> The variable i is declared at the start of function btrfs_qgroup_inherit
> however there are two for-loops that redeclare the variable using a C99
> declaration, causes name shadowing. I believe there is no need for this
> local scoping of i in the loop, so replace the declaration in the loops
> with assignments.
> 
> Cleans up clang scan build warnings:
> 
> fs/btrfs/qgroup.c:3194:12: warning: declaration shadows a local variable [-Wshadow]
>  3194 |                 for (int i = 0; i < inherit->num_qgroups; i++) {
>       |                          ^
> fs/btrfs/qgroup.c:3089:6: note: previous declaration is here
>  3089 |         int i;
>       |             ^
> fs/btrfs/qgroup.c:3321:12: warning: declaration shadows a local variable [-Wshadow]
>  3321 |                 for (int i = 0; i < inherit->num_qgroups; i++)
>       |                          ^
> fs/btrfs/qgroup.c:3089:6: note: previous declaration is here
>  3089 |         int i;
>       |             ^
> 
> Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
> ---
>  fs/btrfs/qgroup.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c
> index ce446d9d7f23..b1f93dbf468c 100644
> --- a/fs/btrfs/qgroup.c
> +++ b/fs/btrfs/qgroup.c
> @@ -3191,7 +3191,7 @@ int btrfs_qgroup_inherit(struct btrfs_trans_handle *trans, u64 srcid,
>  			ret = -ENOMEM;
>  			goto out;
>  		}
> -		for (int i = 0; i < inherit->num_qgroups; i++) {
> +		for (i = 0; i < inherit->num_qgroups; i++) {

We want to use the for(...) local definitions, so this should change the
function scope 'i'.